Hitachi H8/3692 ユーザーズマニュアル
Rev. 1.0, 07/01, page 266 of 372
PSS :
LVDCR :
LVDSR :
LVDCR :
LVDSR :
Prescaler S
Low-voltage-detection control register
Low-voltage-detection status register
Low-voltage-detection control register
Low-voltage-detection status register
Legend
CK
R
PSS
R
S
Q
OVF
Vreset
Vint
LVDCR
LVDSR
Reference
voltage
voltage
Analog-noise
cancellation circuit
cancellation circuit
Analog-noise
cancellation circuit
cancellation circuit
Interrupt
control
circuit
control
circuit
Internal reset
signal
signal
Interrupt
request
request
Inter
nal data b
u
s
Power-
supply
voltage
supply
voltage
+
-
+
-
Figure 17-1 Block Diagram of the Power-on Reset Circuit and Low-Voltage Detection
Circuit
17.2
Register Descriptions
The low-voltage detection circuit has the following registers. For details on register addresses and
register states during each process, refer to section 19, Internal I/O Registers.
register states during each process, refer to section 19, Internal I/O Registers.
•
Low-voltage-detection control register (LVDCR)
•
Low-voltage-detection status register (LVDSR)
17.2.1
Low-Voltage-Detection Control Register (LVDCR)
LVDCR is an 8-bit readable/writable register. Settings in this register enable or disable the low-
voltage detection circuit, set the detection levels for the LVDI function, enable or disable
generation of an interrupt when the power-supply voltage rises above or falls below the respective
levels, and enable or disable the LVDR function.
voltage detection circuit, set the detection levels for the LVDI function, enable or disable
generation of an interrupt when the power-supply voltage rises above or falls below the respective
levels, and enable or disable the LVDR function.